One or more rear window decorative panels may be positioned between a vehicle rear seat and a vehicle trunk in consideration for vehicle interior functionality. The rear window decorative panel are often formed of glass fiber reinforced polypropylene (PP) composite materials for cost efficiencies.
In certain existing designs, a number of breather holes may be formed by directly punching on the decorative panel over a punching die during molding. However, the thus-formed decorative panel may often be over-stretched during the punching process, and unpleasant stress edges may result. Chinese patent application publication CN103407502A discloses a PP honeycomb panel, where periphery seal is used around the PP panel in an effort to reduce stress edges.
Another solution in the industry is to cover the breather holes on the decorative panel to conceal the stress edge.